Color imaging devices contain two or more cartridges. Each transfers a different color of toner to a media sheet as required to produce a full color copy of a toner image. A common imaging device includes four separate color cartridges—cyan, yellow, magenta, and black. Image formation for each of the four colors includes moving toner from a reservoir to an imaging unit where toned images, black or color are formed on photoconductive (PC) drums prior to transfer to a media sheet or to an intermediate transfer member (ITM) for subsequent transfer to a media sheet.
When black-only imaging, mechanisms exist to separate or retract the PC drums for the colored toners from contacting the ITM so their respective motors can be stopped. As this stops the drums from rotating, color toner is not consumed. The mechanisms, however, add complexity and cost. Alternatively, PC drums for the colored toners are not retracted from contacting the ITM, but allowed to skid. This, however, causes an electrostatic charge to develop on the surfaces of the drums. To avoid ESD imaging defects, the drums are rotated occasionally to fully recharge them for subsequent imaging. The rotation uses colored toner even though no colored imaging takes place. The rotation also wears the drums. This can lead to early replacement. A need exists to overcome the foregoing problems.